New cabinet, Internet slows

Hey all. Hope you are enjoying the Bank Holiday weekend. Just a quick question. My cabinet had recently had an Infinity cabinet stuck next to it so Fibre should be here soon. The RFS date has actually been brought forward to June 1st from June 30th although checker still says no. Anyway, at the same time they replaced the old PCP cabinet and since the installation my download speeds have dropped a little from 1.7 - 1.8 Mbps (very slow anyway) to 1.2Mbps. Anyone know why this might be? Thanks.

Without seeing full attenuation, sync and noise margin figures it is hard to say. both before and after.

Possibly the line being changed around if the ADSL was running has caused the DLM system to slow you down by raising the target noise margin by 3dB